Low-temperature conditions of potential propellant fluids, such as hydrogen or natural gas, could diminish the volume occupied for their storage, keeping a high energy content, since the density increases lowering their temperature. This aspect makes the cryogenic reservoirs attractive especially for the decarbonization of mobility sectors, in which it is important to minimize the occupied space maintaining the same energy content, maximizing the volumetric energy density. The research in this field is relatively new and has a huge potential for advancement in both technology and knowledge. A crucial role in cryogenic reservoirs is played by the insulation system working in cryogenic conditions, emphasising the importance of optimizing their thermal performance for the spread of cryogenic applications in the market.